With continuous expansion of the vehicle market, there are more and more vehicle users. Therefore, pressure on traffic is further intensifying, and traffic safety concerns have received increasing attention. For example, when changing lane while driving, the driver must be very careful, because a traditional way of determining whether another vehicle is present behind the vehicle in a lane change mainly relies on rearview mirrors of the vehicle, however some zones, i.e., blind zones, cannot be seen through the rearview mirrors due to the limited field of view of the rearview mirrors. Therefore, in the case of presence of a vehicle in the blind zones, it is very common for a collision between the vehicle in a lane change and the vehicle in the blind zones.
The conventional exterior rearview mirrors have drawbacks of small field of view and large blind zones. Many traffic accidents occur due to a blind zone in the rear side region of the vehicle when overtaking or changing lane. To this end, many techniques of the prior art utilize an optical principle to decrease the radius of curvature of the rearview mirror so as to provide an increased field of view. However, this may bring about distortion of images in the rearview mirrors, which may cause wrong judgment of the drivers and thus lead to dangerous situations. Some other designs for eliminating blind zones also have a poor effect on completely eliminating the blind zone in the rear side region of the vehicle. Some techniques of the prior art involve installation of a camera on the exterior of the vehicle and a display device inside the vehicle. However, in this case, the drivers have to observe the rearview mirrors and the display device at the same time, and are thus distracted, and dangerous situations may thus be caused.